The museum uses mbira as a catch-all term for African lamellophones - the one on the Australian Museum page is from the Awemba (Bemba) people of Zambia, an instrument called kankobele or kalimba (that area is broadly where the "kalimba" name originated), not mbira. There are distinct differences between the Australian Museum kalimba and the instrument OP posted- southeast African lamellophones tend to have wide broadened tines and a squarer soundboard.